First of all, a pregnancy test has to be done. After that sensitive urinary ELISA test is conducted. If it is negative then there is no sign of ectopic pregnancy. This may be confirmed with a blood sample taken later. Vaginal ultrasound can clearly confirm pregnancy in the womb from about 4.5-5 weeks onward. Once confirmed, an ectopic pregnancy is once again virtually excluded (except in the case of the extremely rareheterotopic pregnancy). Sometimes, vaginal ultrasound scan can clearly show an ectopic pregnancy in the tube next to the uterus.